PECAM1 and pulmonary fibrosis: In the lungs of mice from intact control and with partially reversible pulmonary fibrosis and in mice with partially reversible pulmonary fibrosis, treated by singularly and consistently administered pegHYAL and spiperone, CD45- -cells were determined expressing on the surface CD44, CD73, CD90, CD106 and were negative for CD31 and CD34 (Fig 5).